Relief valve



June zo, 1944. A l. PARKER' RELIEF VALVE Filed Maron 51, 1.941

Patented June 20, 1944 RELIEF VALVE Arthur L. Parker, Cleveland, Ohio, assignor to The Parker Appliance Company, Cleveland, Ohio, a corporation of Ohio Application March 31, 1941, Serial No.. 386,221

1v Claim. (Cl. 137-53) therewith.

An object of the invention is to provide a relief valve which is so constructed that back pressure on the exhaust side of the valve will not cause uid to leak through the valve into the pressure line.

'A further object of the invention is to provide an auxiliary valve control which is associated with the relief valve and is so constructed that said auxiliary control valve may be placed at a point distant from the relief valve and thereby associated with the control panel for the fluid pressure system.

In the drawing:

Figure 1 is a sectional view through the relief valve lengthwise thereof, and also through an automatically operated controlvalve associated with the relief valve.

Figure 2 is a view in side elevation and showing more or less diagrammatically a manually operated auxiliary control Vvalve associated with the relief valve.

Figure 3 is a sectional view longitudinally of the valve casing showing a slightly modied form of relief valve structure.

Figure 4 is a detailed section of the sleeve insert associated with the ball valve in Figure 3.

Figure 5 is an end view of the valve insert.

The relief valve includes a valve casing I having a pipe thread connection 2 to which a pipe may be joined that leads to the pressure lines. Said casing is also provided with a pipe thread connection 3 to which a pipe may be joined that leads to the exhaust side of the pressure line. The pipe connection 2 is threaded into the valve casing and carries a valve seat 4 with which a valve 5 cooperates. The valve 5 is carried by a valve stem 6.

A sleeve member 1 is threaded into the upper end of the valve stem. Said sleeve is provided with a head which contacts with a gasket 8.

Below the gasket 8 is a metal ring 9, and below the metal ring 9 is a gasket I0. The gasket 8 is so constructed as to prevent leakage of the pressure iluid in the chamber II'. The gasket I0 is so constructed as to prevent leakage due to back pressure on the exhaust side.

Ihe valve is provided with a tapered end` I2 which engages the valve seat 4. There is a relatively restricted passage I3 leading through the lower end of the valve into a passage I4 which is connected with the chamber II. A spring I5 bears against the shoulder at the lower end of 'the sleeve 1 and normally urges the valve against,

the seat 4. v

As shown in Figure 3, the yvalve casing I' and the valve seat 4 are ofthe same construction as shown in the relief valve of Figure 1. Likewise, the sleeve 1 and the spring I5 are associated with the valve for holding it seated. In this form of valve structure there is a sleeve insert I6 having a passage I1 therethrough. The opening leading from the lower end of the valve indicated at-l8 is of considerably larger size than opening I3. At the upper end of this opening I8 there is a valve chamber for a ball valve I9. At the lower side of this 'ball is a valve seat 20. The lower end of the sleeve insert has one or more V-shaped grooves 2|. This ball is of slightly smaller diameter than the diameter of the chamber in which it is located so that fluid pressure on the system will pass up through opening I8 around the ball when the ball is lifted from its seat and through the sleeve insert into the chamber II at the upper end of the valve casing.

The auxiliary control valve as shown in Fig. l includes a casing 22 having a chamber 23 therein. The casing is provided with a base member 24 which may be secured to a control panel by any suitable means. There is an opening 25 through the base leading into chamber 23. A pipe 26 is connected to the base at the opening 25. This pipe may be of any desired length and at its other end it Ais connected to an opening 26a through the Wall of the valve casing I.

Surrounding the opening 25 is a valve seat 21 with which a ball valve 28 makes contact. A plate 29 bears against the ball and is provided with a flange contacting with the Wall of the chamber 23 for guiding the same. A spring 30 bears on the plate 29 at one end and at its other end against an abutment shoulder 3| carried by a stem 32 which is threaded into a cap nut 33. The cap nut 33 is in turn threaded into the valve casing 22. Mounted on the stem 32 is a locknut 34. A closure cap 35 covers this stem 32 and is detachably connected to the valve casing.

When it is desired to change the tension on the spring 30, the cap is removed and the stem 32 adjusted for this purpose.

As above noted, this auxiliary control valve may be placed at a point distant from the relief valve and is connected therewith through the pipe 28. The exposed area I2 of the valve is slightly less than the exposed area of the sleeve 1. Fluid pressure on the line causes fluid `to pass through the opening I3 into the chamber II at the upper end of the relief valve casing. 'Ihis fluid pressure passes through the pipe 2i to the auxiliary control valve in the casing 22. .When the pressure is insumcient to raise the ball`2l oi! its seat against the spring and the pressure of the iiuid on the upper side of the sleeve l, the relief valve will remain closed. When the fluid pressure -on the line rises above a predetermined setting of the tension on the spring 30, then the ball 28 will be forced of! its seat and i'luid will pass into the chamber of the auxiliary valve and out through the pipe ll to the exhaust side of the fluid `pressure system. This reduces the pressure in the chamber l`l so that the pressure on the underside I2 of the relief valve will lift it from itsseat. The fluid passing to the exhaust side of the system through the pipe connection I will relieve the pressure on the line. This relief of the pressure on the line will not cause the valve to close quickly and chatter for the reason that the passage I3 is relatively small and the pressure in the chamber Il will not build up so as to permit the spring to close the valve i until the ball valve 23 of the auxiliary control closes.

In the construction shown in Figure 3 the rel lief valve will operate in the manner above described to relieve the pressure on the line. The opening Il -is larger than the opening I3 but thereis a restricted passage around the ball and also a restricted passage through the V-groove 2l when the ball is lifted by pressure against the lower end of the sleeve insert I8. Any back pressure on the exhaust line which causes fluid to pass the gasket l' intoA the chamber Il will act through the passage I1 against the ball and cause the ball is to engage the seat at the lower side thereof and thus the fluid is.prevented from asuma l which the exhaust pipe Il is also connected. In4 thisvalvecasingis aneedlevalve l. cooperating with. a seat for closing ci! connection with the pipe 2C. 'The needle valve is controlled by a-h'and wheel 3l. This manually operated auxiliary control valve may be located at the control panel and at a point distant from the relief valve. This needle valve is normally closed. When pressure on the line rises above a selected working pressure and it is desired to reduce the same, then the needle valve is opened and this will cause the relief valve to open and reduce the pressure. It is to be understood that the relief valve of Figure 3 can be used in connection with either of the 'auxiliary control valves shown in Figures l and 2.

I claim:

In a iiuid pressure system, a relief valve including a valve casing having an inlet for connection to a iluid pressure line, a valve seat in said casing, said valvecasing having a port for exhaust' -abovethe valve seat, aavalve mounted for reciprocation in the lvalve casing and adapted to engage .said seat, said valve casing having a chamber above the valve, a passage extending through the valve and connecting the inlet with the chamber above the valve, the area of the upper end of the valve subjected to pressure being slightly greater than the area ofthe lower end of the valve subjected to iiuid pressure when the valve is closed, means for exhausting the pressure fluid from the chamber above the valve, said passage in the valve being enlarged at the upper portion of the valve and having a ball seat at the bottom of said enlargement, a ball dimensioned to have restricted freedom to move in said enlarged passage so as to provide for restricted passage thereabout in the'enlarged passage and adapted to engage the ball seat for closing the passage when the pressure is applied to the ball from above, a plug in said valve above said ball, said plug being spaced from the ball and having a central opening therethroughwith a V-notch in the edge contacted by the bali providing a re- 

